This paper develops the concept of network sustainability. To become and stay sustainable, distributed research infrastructures must satisfy present needs while at the same time be flexible and resilient to meet future requirements. For this it is not enough to merely build a resilient economic model and be technically viable. Research infrastructures that can understand, address and shape future needs have a sustainable community network. Clear characteristics of a research infrastructure with a sustainable network are that partners gain access to other networks and interest groups, that knowledge, information and expertise is shared freely among partners, that the infrastructure increases partners’ visibilities and vice versa, and that partners are enabled to stay current and state-of-the-art. This is shown on OPERAS (open access in the european research area through scholarly communication), a research infrastructure for open scholarly communication in the social sciences and humanities, and its partner the Max Weber Foundation, a German research institution.